Up-and-coming rapper Luci4 was found dead in an L.A. residence on Sunday ... and now we're learning more about his movements hours prior to his death. We broke the news ... the rapper -- best known for his viral hit "BodyPartz" -- was found dead at a friend's house at the age of 23. His cause of death has yet to be determined ... and his family wants answers. The father of Luci4 -- born James Dear IV -- tells TMZ ... last Saturday, his son was running late to catch a 10:52 PM flight to Miami